windows XP sound

i have a weird issue with sound.

i recently installed XP in a virtual machine, then added precision simulator (aka PS1) version 1.3 and 747IPC. PS1 expects a soundblaster card, in case that matters. anyway, the first few times i launched it, it ran normally, sound and all. but the weird thing is, today i launched it again, and no sound. no engine noise, no cockpit sounds, no ATIS, no co-pilot, no ATC, no nothing. of course i want the sound back because it makes the whole thing even more realistic. and if i can't hear the ATC instructions, i'll have to keep my eye on the "window" where they appear as text, keeping my attention away from other things. IOW, it's just not ideal.

problem is, i don't even know if it's a parallels issue, an XP issue or an issue with the software i use.

can anyone point me in the right direction?